Aqueous resin based inkjet inks

Abstract

An inkjet ink includes a) an aqueous medium; and b) capsules composed of a polymeric shell surrounding a core; wherein the capsules are dispersed in the aqueous medium using a dispersing group covalently bonded to the polymeric shell; the dispersing group is selected from the group consisting of a carboxylic acid or salt thereof, a sulfonic acid or salt thereof, a phosphoric acid ester or salt thereof, a phosphonic acid or salt thereof, an ammonium group, a sulfonium group, and a phosphonium group; the core contains one or more chemical reactants capable of forming a reaction product upon application of heat and/or light; and the capsules have an average particle size of no more than 4 μm as determined by dynamic laser diffraction.

The invention claimed is: 
     
       1. An inkjet ink comprising:
 an aqueous medium; and 
 capsules including a polymeric shell surrounding a core; wherein 
 the capsules are dispersed in the aqueous medium including a dispersing group covalently bonded to the polymeric shell; 
 the dispersing group is selected from the group consisting of a carboxylic acid or salt thereof, a sulfonic acid or salt thereof, a phosphoric acid ester or salt thereof, a phosphonic acid or salt thereof, an ammonium group, a sulfonium group, and a phosphonium group; 
 the core includes one or more chemical reactants that form a reaction product upon application of heat, and the one or more chemical reactants includes a thermally curable compound; and 
 the capsules have an average particle size of no more than 4 μm as determined by dynamic laser diffraction. 
 
     
     
       2. The inkjet ink according to  claim 1 , wherein the dispersing group is a carboxylic acid or salt thereof. 
     
     
       3. An inkjet printing method comprising the steps of:
 jetting an inkjet ink according to  claim 2  on a substrate; and 
 applying heat to the inkjet ink jetted on the substrate to form a reaction product from the one or more chemical reactants in the capsules. 
 
     
     
       4. The inkjet printing method according to  claim 3 , wherein the substrate is a textile, leather, glass, pharmaceutical packaging, or food packaging. 
     
     
       5. The inkjet ink according to  claim 1 , wherein the polymeric shell includes a polymer selected from the group consisting of a polyamide, a melamine based polymer, a poly(urea-urethane) polymer, and copolymers thereof. 
     
     
       6. The inkjet ink according to  claim 1 , wherein the thermally curable compound is a blocked isocyanate. 
     
     
       7. The inkjet ink according to  claim 6 , further comprising an optothermal converting agent. 
     
     
       8. The inkjet ink according to  claim 7 , wherein the optothermal converting agent includes an infrared dye. 
     
     
       9. The inkjet ink according to  claim 6 , wherein the aqueous medium includes a polymeric latex particle. 
     
     
       10. The inkjet ink according to  claim 6 , further comprising a colorant. 
     
     
       11. The inkjet ink according to  claim 1 , further comprising an optothermal converting agent. 
     
     
       12. The inkjet ink according to  claim 11 , wherein the optothermal converting agent includes an infrared dye. 
     
     
       13. The inkjet ink according to  claim 1 , further comprising a colorant. 
     
     
       14. The inkjet ink according to  claim 1 , wherein the aqueous medium includes a polymeric latex particle. 
     
     
       15. The inkjet ink according to  claim 1 , wherein the polymeric shell is crosslinked.